Hybrid overvoltage protection device and assembly

ABSTRACT

In one embodiment, an overvoltage protection device (100) may include a crowbar device (106), where the crowbar device (106) includes a first crowbar terminal (115), the first crowbar terminal (115) connected with a first external voltage line (102). The overvoltage protection device (100) may further include a transient voltage suppression (TVS) device (108), where the TVS device (108) includes a second TVS terminal (121), the second TVS terminal (121) connected with a second external voltage line (104). The crowbar device (106) and the TVS device (108) may be arranged in electrical series between the first crowbar terminal (115) and the second TVS terminal (121).

BACKGROUND Field

Embodiments relate to the field of circuit protection devices, and moreparticularly to semiconductor devices for protection against overvoltageevents.

Discussion of Related Art

Semiconductor devices are widely used to provide protection againsttransient conditions, such as transient overvoltage events or surgeevents, by taking advantage of the properties of P/N junctions. In atransient voltage suppression (TVS) device, voltage may be clamped to alevel characteristic of the particular clamping device. Examples of aTVS device are avalanche diodes. A Zener diode may also providetransient voltage protection. The principle of operation in TVS deviceslies in the reverse voltage breakdown of a P/N junction in a diode,which “breakdown voltage” acts as a clamping voltage to limit voltageacross the device. The breakdown voltage is characteristic of theparticular device design, such as the doping characteristics of the Pregion and N region of the device. For applications such as circuitprotection for components coupled to a DC power line, a TVS device maybe designed to provide protection based upon a constant overvoltagerating, as well as a maximum voltage for a circuit or component to beprotected. In some instances, the constant over voltage level that isneeded may entail design of a TVS diode having a relatively highbreakdown voltage so that the breakdown is close to the constant overvoltage level. This increased breakdown voltage for a TVS device maylead to the inability to clamp voltage during a transient overvoltageevent to below the maximum voltage allowed by a circuit, leading todamage or destruction of the circuit or component to be protected.

It is with respect to these and other issues the present disclosure isprovided.

SUMMARY

In one embodiment, an overvoltage protection device may include acrowbar device, where the crowbar device includes a first crowbarterminal, the first crowbar terminal for connection to a first externalvoltage line. The overvoltage protection device may further includetransient voltage suppression (TVS) device, where the TVS deviceincludes a second TVS terminal, the second TVS terminal for connectionto a second external voltage line. The crowbar device and the TVS devicemay be arranged in electrical series between the first crowbar terminaland the second TVS terminal.

In another embodiment, an overvoltage protection assembly may include afirst semiconductor chip, where the first semiconductor chip comprises acrowbar device. The overvoltage protection assembly may also include asecond semiconductor chip, where the second semiconductor chip comprisesa TVS device and is electrically connected to the first semiconductorchip. The overvoltage protection device may comprise a first externalterminal forming contact with the crowbar device, where the firstexternal terminal is for connection to a first external voltage line,and may further comprise a second external terminal forming contact withthe TVS device, where the second external terminal is for connection toa second external voltage line. The crowbar device and the TVS devicemay be arranged in electrical series between the first external terminaland the second external terminal.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 presents a circuit representation of one implementation of anovervoltage protection arrangement according to embodiments of thedisclosure;

FIG. 2 presents a circuit representation of one implementation of anovervoltage protection arrangement according to other embodiments of thedisclosure;

FIG. 3 presents a circuit representation of one implementation of anovervoltage protection arrangement according to further embodiments ofthe disclosure;

FIG. 4 presents a circuit representation of one implementation of anovervoltage protection arrangement according to other embodiments of thedisclosure;

FIG. 5 presents a circuit representation of one implementation of anovervoltage protection arrangement according to further embodiments ofthe disclosure;

FIG. 6 presents one scenario of operation of an overvoltage protectiondevice according to embodiments of the disclosure;

FIG. 7 presents a side cross-sectional view of a hybrid overvoltageprotection device according to various embodiments;

FIG. 8 presents a side cross-sectional view of another hybridovervoltage protection device according to various embodiments;

FIG. 9 presents a side cross-sectional view of another hybridovervoltage protection device according to various embodiments;

FIG. 10 presents an exemplary current-voltage curve for an overvoltageprotection device according to embodiments of the disclosure; and

FIG. 11 presents a comparison of current-voltage plots for a knowndevice and an overvoltage protection device arranged according toembodiments of the disclosure.

DESCRIPTION OF EMBODIMENTS

The present embodiments will now be described more fully hereinafterwith reference to the accompanying drawings, in which variousembodiments are shown. The embodiments may be embodied in many differentforms and are not to be construed as limited to the embodiments setforth herein. These embodiments are provided so that this disclosurewill be thorough and complete, and will fully convey the scope of theembodiments to those skilled in the art. In the drawings, like numbersrefer to like elements throughout.

In the following description and/or claims, the terms “on,” “overlying,”“disposed on” and “over” may be used in the following description andclaims. “On,” “overlying,” “disposed on” and “over” may be used toindicate when two or more elements are in direct physical contact withone another. The terms “on,”, “overlying,” “disposed on,” and over, mayalso mean when two or more elements are not in direct contact with oneanother. For example, “over” may mean when one element is above anotherelement and not in contact with another element, and may have anotherelement or elements in between the two elements. Furthermore, the term“and/or” may mean “and”, it may mean “or”, it may mean “exclusive-or”,may mean “one”, may mean “some, not all”, may mean “neither”, and/or itmay mean “both.” The scope of claimed subject matter is not limited inthis respect.

The present embodiments are generally related to overvoltage protectiondevices, and in particular, to hybrid devices or assemblies providingovervoltage protection. In various embodiments, a TVS device and crowbardevice may be combined to form a hybrid device or hybrid assembly, inunique configurations to provide transient overvoltage protection.Examples of crowbar devices include devices that are based upon the useof silicon controlled rectifiers (SCR), thyristors, TRIACs, SIDACs, andSIDACtors® (®SIDACtor is a trademark of Littelfuse, Inc.). One advantageafforded by crowbar devices, such as silicon controlled rectifiers(SCR), SIDACs and SIDACtors, is the ability to respond rapidly to anovervoltage event and clamp the voltage to an acceptable level. Inparticular, when current flowing through the SIDAC and SIDACtor exceedsa switching current, the SIDAC and SIDACtor acts as a “crowbar” andsimulates a short circuit condition. Unlike conventional transientvoltage suppression (TVS) clamping devices such as diodes, the advantageof a crowbar type protection device is that the crowbar protectiondevice is not damaged by overvoltage. In the present embodiments, when atransient voltage is experienced that exceeds a breakdown voltage of thehybrid device, the crowbar device portion of the hybrid device may betriggered to an ON state, while the crowbar device and TVS device act inconcert to clamp the voltage to a lower voltage level.

FIG. 1 presents a circuit representation of one implementation of anovervoltage protection arrangement according to embodiments of thedisclosure. In particular, an overvoltage protection assembly 100 isimplemented between a first electrical line 102 and second electricalline 104. The first electrical line 102 and second electrical line 104may be coupled to a DC C power source, thus representing DC power linesin one implementation.

In operation, the overvoltage protection assembly 100 may act to limitvoltage coupled to a DC source. In the example of FIG. 1, theovervoltage protection assembly 100 may protect a circuit 110 bylimiting the voltage or energy that passes through the circuit 110during an overvoltage event. The circuit 110 may represent anyelectrical device, electronic device, optical device, opto-electonicdevice, circuit, machine, or combination of these components. Theembodiments are not limited in this context.

In various embodiments, the overvoltage protection assembly 100 may actas a uni-directional device that provides response to a surge thatgenerates an overvoltage in one direction between first electrical line102 and second electrical line 104, appropriate for protection ofcircuitry coupled to a DC power source, for example.

The overvoltage protection assembly 100 may include a first discretecomponent 116 and a second discrete component 118, where the firstdiscrete component 116 and second discrete component 118 areelectrically connected to one another in electrical series between thefirst electrical line 102 and the second electrical line 104. As such,the first discrete component 116 and the second discrete component 118may be located adjacent to one another, remote from one another, and inany convenient spatial relationship to one another.

In this embodiment, as well as other embodiments, the overvoltageprotection assembly may include a crowbar device, shown as crowbardevice 106, and a transient voltage suppression device, shown astransient voltage suppression device 108. An example of a suitableunidirectional crowbar device is a unidirectional SIDAC orunidirectional SIDACtor, while an example of a suitable unidirectionalTVS device is a Zener diode or avalanche diode. The embodiments are notlimited in this context. The crowbar device 106 may include a firstcrowbar terminal 115 that is connected to a first external voltage line,shown as the first electrical line 102, and a second crowbar terminal117. The second crowbar terminal 117 of the crowbar device 106 may beconnected to a first TVS terminal 119 of the transient voltagesuppression device 108. The transient voltage suppression device 108 mayfurther include a second TVS terminal 121 connected to the secondexternal voltage line, shown as second electrical line 104.

In operation, when an overvoltage event occurs, wherein the voltagebetween the first electrical line 102 and second electrical line 104exceeds a certain value, the overvoltage protection assembly may betriggered to respond to the overvoltage event in a manner that protectsthe circuit 110. For example, the crowbar device 106, initially in astandby or OFF state, may develop an excess current in response to acertain voltage value generated during a power surge, as in knowncrowbar devices. In particular, at a characteristic voltage, orbreakover voltage, the current may trigger the crowbar device 106 torapidly transition to an ON state, where the voltage rapidly drops(folds back) to a lower voltage, causing the external transient voltagebetween first electrical line 102 and second electrical line 104 to bediverted through the overvoltage protection assembly 100. In conjunctionwith the transient voltage suppression device 108, the overvoltage eventmay then be clamped at a clamp voltage determined by the exactcharacteristics of the transient voltage suppression device 108 andcrowbar device 106, until the power surge is dissipate, when the crowbardevice 106 may reset to an OFF state.

FIG. 2 presents a circuit representation of one implementation ofanother overvoltage protection arrangement according to embodiments ofthe disclosure. In particular, an overvoltage protection assembly 120 isimplemented between the first electrical line 102 and second electricalline 104. In this embodiment, the first electrical line 102 and secondelectrical line 104 may be coupled to AC voltage source, such as a ACpower source, thus representing AC power lines in one implementation.

The overvoltage protection assembly 120 may include a first discretecomponent 136 and a second discrete component 138, where the firstdiscrete component 136 and the second discrete component 138 areelectrically connected to one another in electrical series between thefirst electrical line 102 and the second electrical line 104. In thisembodiment, as well as other embodiments, the overvoltage protectionassembly may include a bidirectional crowbar device, shown as crowbardevice 126, and a bidirectional overvoltage protection device, shown astransient voltage suppression device 128. An example of a suitablebidirectional crowbar device is a SIDAC or SIDACtor, while an example ofa suitable TVS device is a pair of TVS diodes having acathode-to-cathode configuration, as shown in FIG. 2. The overvoltageprotection assembly 120 may be configured with terminal configurationsas in the overvoltage protection assembly 100.

According to known principles, a bi-directional or symmetricalsemiconductor crowbar device may provide an effective AC powerlineprotection. Under normal operation when AC voltage does not exceed abreakover voltage, such a semiconductor crowbar device does not turn on.When AC peak voltage or a surge transient voltage exceeds the breakovervoltage, the semiconductor crowbar device may enter an ON state, asdiscussed above, placing the semiconductor crowbar device in a lowvoltage ON state, and triggering the external transient voltage to bediverted.

In the embodiments as shown in FIG. 2, when a bidirectionalsemiconductor crowbar device is coupled together with a bidirectionalTVS device, the resulting overvoltage protection device may form a lowclamping voltage bi-directional surge protection device.

FIG. 3 presents a circuit representation of one implementation ofanother overvoltage protection arrangement according to embodiments ofthe disclosure. In particular, an overvoltage protection assembly 140 isimplemented between a first electrical line 102 and second electricalline 104. The first electrical line 102 and second electrical line 104may be coupled to DC voltage source, such as a DC power source, thusrepresenting DC power lines in one implementation.

In operation, the overvoltage protection assembly 140 may act to limitvoltage coupled to a DC source. In the example of FIG. 3, theovervoltage protection assembly 140 may protect the circuit 110, asdiscussed above. The overvoltage protection assembly 140 may include acomponent 146 that includes a unidirectional crowbar device, shown ascrowbar device 106, and a unidirectional transient voltage suppressiondevice, shown as transient voltage suppression device 108, discussedabove. In this embodiment, different from FIG. 1, the crowbar device 106and transient voltage suppression device 108 are housed in a commoncomponent, where the component 146 may represent a common semiconductorsubstrate, such as a semiconductor die, or a package that housesdifferent die. Operation of the overvoltage protection assembly 140 mayproceed similarly to the operation of overvoltage protection assembly100, discussed above.

FIG. 4 presents a circuit representation of one implementation ofanother overvoltage protection arrangement according to embodiments ofthe disclosure. In particular, an overvoltage protection assembly 160 isimplemented between a first electrical line 102 and second electricalline 104. The first electrical line 102 and second electrical line 104may be coupled to AC voltage source, such as a AC power source, thusrepresenting AC power lines in one implementation.

In operation, the overvoltage protection assembly 160 may act to limitvoltage coupled to an AC source. In the example of FIG. 4, theovervoltage protection assembly 160 may protect the circuit 110, asdiscussed above. The overvoltage protection assembly 160 may include acomponent 166 that includes a bidirectional crowbar device, shown ascrowbar device 126, and a bidirectional transient voltage suppressiondevice, shown as transient voltage suppression device 128, discussedabove. In this embodiment, different from FIG. 2, the crowbar device 126and transient voltage suppression device 128 are housed in a commoncomponent, where the component 166 may represent a semiconductor die ora package housing different die. Operation of the overvoltage protectionassembly 160 may proceed similarly to the operation of overvoltageprotection assembly 120, discussed above.

FIG. 5 presents a circuit representation of one implementation of anovervoltage protection arrangement, according to further embodiments ofthe disclosure. In this example, in addition to the crowbar device 126and transient voltage suppression device 128, the overvoltage protectionassembly 120 includes a snubber circuit 196, which circuit may include acapacitor and resistor, or other known snubber circuit arrangement. Thesnubber circuit 196 may provide better reduction on overshoot voltage,and may be effective for very rapid transient voltages, whose durationmay span between nanoseconds to several microseconds. The specificcapacitance and resistance of snubber circuit 196 may be based upon theinrush/overshoot pulse width to be treated by transient voltagesuppression device 128.

FIG. 6 presents one scenario of operation of an overvoltage protectiondevice according to embodiments of the disclosure. The voltagedifference between a line voltage 170 and a line voltage 172 is shownschematically along the vertical direction in the figure, while time isrepresented along the horizontal. A constant overvoltage level 174 isshown as well as a maximum voltage 176, which voltage may be a maximumallowed circuit voltage. A voltage surge 178 is shown, where the peakvoltage of the voltage surge 178 does not exceed the maximum voltage176, thus protecting the circuit 110 from damage. At the same time,longer term voltage excursions that are below the constant overvoltagelevel may be tolerated.

FIG. 7 presents a side cross-sectional view of a hybrid overvoltageprotection device 210 according to various embodiments. The hybridovervoltage protection device 210 is embodied in semiconductor substrate180, such as a monocrystalline silicon wafer or chip. The hybridovervoltage protection device 210 presents the equivalent of anelectrical circuit having a unidirectional crowbar device and aunidirectional TVS device arranged in electrical series with oneanother, as shown.

With reference to FIG. 1, for example, the semiconductor substrate 180includes a first surface 182, which surface may form a portion of thefirst crowbar terminal 115, as well as a second surface 184, oppositethe first surface 182, and forming a portion of the second TVS terminal121. The semiconductor substrate 180 may further include a first N-dopedregion 186, where the first N-doped region 186 is disposed adjacent tothe first surface 182. The semiconductor substrate 180 may also includea first P-doped region 188, where the first P-doped region 188 isdisposed adjacent the first N-doped region 186 and surrounds the firstN-doped region 186 within the semiconductor substrate 180. Thesemiconductor substrate 180 may also include a second N-doped region190, the second N-doped region 190 being disposed adjacent the firstP-doped region 188, where the second N-doped region 190 and firstN-doped region 186 do not share a common interface. Generally, thesecond N doped region 190 may be more lightly doped than the first Ndoped region. The semiconductor substrate 180 may also include a thirdN-doped region 194, where the third N-doped region 194 is disposedadjacent the second surface 184. The semiconductor substrate 180 mayalso include a second P-doped region 192, where the second P-dopedregion 192 is disposed between the second N-doped region 190 and thethird N-doped region 194, and surrounds the third N-doped region 194within the semiconductor substrate 180. Generally, the top four regions,(186,188,190,192) may constitute a crowbar device, while the bottom 2layers (192, 194) may constitute a TVS device. In some embodiments, thefirst N-doped region 186 may have a doping concentration of 1.0×10¹⁸cm⁻³ to 1.0×10²¹ cm⁻³, the first P-doped region 188 may have a dopingconcentration of 1.0×10¹⁶ cm⁻³ to 3.0×10¹⁸ cm⁻³, the second N-dopedregion 190 may have a doping concentration of 1×10¹³ cm⁻³ to 1.0×10¹⁷cm⁻³, the second P-doped region 192 may have a doping concentration of1×10¹⁵ cm⁻³ to 1×10⁸ cm⁻³, and the third N-doped region 194 may have adoping concentration of 1×10¹⁸ cm⁻³ to 1.0×10²¹ cm⁻³. In one embodiment,the first N-doped region 186 may have a doping concentration of 1.0×10²⁰cm⁻³, the first P-doped region 188 may have a doping concentration of1.0×10¹⁸ cm⁻³, the second N-doped region 190 may have a dopingconcentration of 1.0×10¹⁴ cm⁻³, the second P-doped region 192 may have adoping concentration of 4.5×10¹⁶ cm⁻³, and the third N-doped region 194may have a doping concentration of 1.0×10²⁰ cm⁻³.

The hybrid overvoltage protection device 210 may also include an N⁺doped surface region 193, disposed adjacent the first surface 182, andoverlapping the second N-doped region 190 and first P-doped region 188,where the first N⁺ doped surface region 193 is disposed outside of thefirst N-doped region 186. The first N+ doped surface region 193 may havea doping concentration in the range of 1×10¹⁸ cm⁻³ to 1.0×10²¹ cm⁻³ andin particular 1.0×10²⁰ cm⁻³.

FIG. 8 presents a side cross-sectional view of another hybridovervoltage protection device according to various embodiments. Thehybrid overvoltage protection device 220 is embodied in semiconductorsubstrate 180, such as a monocrystalline silicon wafer. The hybridovervoltage protection device 220 presents the equivalent of anelectrical circuit having a unidirectional crowbar device and aunidirectional TVS device arranged in electrical series with oneanother, as shown. A difference in the hybrid overvoltage protectiondevice 220 as compared to hybrid overvoltage protection device 210 isthe provision of N⁺ doped buried regions 202 disposed between the firstP-doped region 188 and the second N-doped region 190, and under thefirst N-doped region 186.

Notably, in the configurations of FIG. 7 and FIG. 8, while thesemiconductor substrate 180 or semiconductor substrate 200 incorporate aTVS device and crowbar device in electrical series, there is no separatesecond crowbar terminal and first TVS terminal. Rather, the two devicesare integrated seamlessly where the two devices share a common dopedlayer (192).

FIG. 9 presents a side cross-sectional view of another hybridovervoltage protection device according to various embodiments. In thisembodiment, a hybrid overvoltage protection device, shown as overvoltageprotection device 230, is arranged differently than in the embodimentsof FIG. 7 and FIG. 8, where the overvoltage protection device 230provides bidirectional TVS device and a bi-directional crowbar device.In the configuration of FIG. 9, the overvoltage protection device 230 isarranged where a crowbar device 234 is located in a first region, and aTVS device 236 is located in a second region, laterally displaced fromthe first region. The crowbar device 234 extends from the first surface182 to the second surface 184, while the TVS device 236 also extendsfrom the first surface 182 to the second surface 184. The overvoltageprotection device 230 further includes an electric isolation region 232,disposed between the crowbar device 234 and the TVS device 236, wherethe electric isolation region 232 also extends between the first surface182 and the second surface 184. The electric isolation region 232 may beformed using an insulating material such as an oxide, or may be formedusing dopant isolation, according to known techniques. The overvoltageprotection device 230 further includes a crowbar device contact 238,serving as a first crowbar terminal, and a TVS device contact 240,serving as a second TVS terminal, each disposed on the first surface182. The crowbar device contact 238 and TVS device contact 240 formelectrical contact to external contact 242 and external contact 244,respectively. The overvoltage protection device 230 further includes abottom contact 246 that serves as a second crowbar terminal and as afirst TVS terminal, and accordingly joins the crowbar device 234 and TVSdevice 236 in electrical series. In this manner the first crowbarterminal and the second TVS terminal of the overvoltage protectiondevice 230 are disposed on the first surface 182 while the secondcrowbar terminal and first TVS terminal are disposed on the secondsurface 184.

As shown in FIG. 9, the crowbar device may include a top N doped region187, arranged adjacent the first surface 182, a middle N-doped region191, and bottom N doped region 195, arranged adjacent the second surface184, where the bottom N doped region 195 and top N doped region 187 areboth heavily doped, that is, are N⁺ regions. In some embodiments, thetop N doped region 187 and the bottom N doped region 195 may have adoping concentration in the range of 1×10¹⁸ cm⁻³ to 1.0×10²¹ cm⁻³ and inparticular 1.0×10²⁰ cm⁻³, the first P doped region 188 and the secondP-doped region 192 may have a doping concentration of 1×10¹⁶ cm⁻³ to5.0×10¹⁸ cm⁻³ and in particular 2.0×10¹⁸ cm⁻³, the N⁺ doped buriedregions 202 may have a doping concentration of 1×10¹⁵ cm⁻³ to 3.0×10¹⁸cm⁻³ and in particular 1.0×10¹⁸ cm⁻³.

As further shown in FIG. 9, the TVS device 236 may include a top P dopedregion 241, arranged adjacent the first surface 182, a bottom P dopedregion 243, arranged adjacent the second surface 184, and anintermediate N doped region 245, disposed between the top P doped region241 and the bottom P doped region 243. The intermediate N doped region245 may have the same doping level as the second N-doped region 190, andmay be doped in the same process as used to form second N doped region190. The three-layer structure of the TVS device 236 accordingly forms apair of TVS diodes having a cathode-to-cathode configuration, as shown.The top P doped region 241 and the bottom P doped region 243 may have adoping concentration of 1×10¹⁸ cm⁻³ to 1×10²⁰ cm⁻³ and in particular5.0×10¹⁹ cm⁻³, the intermediate N doped region 245 may have a dopingconcentration of 1×10¹³ cm⁻³ to 2.0×10¹⁷ cm⁻³ and in particular 7.7×10¹⁶cm⁻³.

Turning now to FIG. 10, there is shown an exemplary current-voltagecurve for an overvoltage protection device according to embodiments ofthe disclosure. In this example, a hybrid overvoltage protection deviceis arranged with a crowbar device and TVS in electrical series betweentwo external voltage lines. The curve 250 shows a first portion 252,representing the breakover voltage of approximately 63 V, and a secondportion 254 representing a clamp voltage where the voltage has foldedback to approximately 55 V.

FIG. 11 presents a comparison of current-voltage plots for a known TVSdevice (right line) and a hybrid overvoltage protection device (leftline) arranged according to embodiments of the disclosure. The clampvoltage Vc is shown as a function of current Ipp of a pulse. Asillustrated, the hybrid overvoltage protection device, including a TVSdevice and crowbar device, provides a much lower clamp voltage for agiven Ipp and the maximum pulse diverted is 70.4 A for the hybridovervoltage protection device, as compared to 54.4 A for a known TVSdevice.

The aforementioned embodiments provide a flexible approach toovervoltage protection that can be tailored to different applications.For example, in a 12 V automotive system may be required to withstand a31V constant overvoltage. For a 122V 188 millisecond 2.5 ohm load dumptransient, the transient clamp voltage may be less than 40 V. A hybriddevice composed of a TVS and crowbar device may be tailored for thisapplication by incorporating a 28 V TVS device where Vc (clampingvoltage) is less than 40 V. An 8V rapid switching crowbar device mayalso be incorporated in the hybrid device so that the 28V TVS device and8V crowbar device in series provide a higher breakover voltage than 31 Vand is less than 40 V.

While the present embodiments have been disclosed with reference tocertain embodiments, numerous modifications, alterations and changes tothe described embodiments are possible without departing from the sphereand scope of the present disclosure, as defined in the appended claims.Accordingly, the present embodiments may not be limited to the describedembodiments, but have the full scope defined by the language of thefollowing claims, and equivalents thereof.

What is claimed is:
 1. An overvoltage protection device, comprising: acrowbar device, the crowbar device including: a first crowbar terminal,the first crowbar terminal for connection to a first external voltageline; and a transient voltage suppression (TVS) device, the TVS devicehaving: a second TVS terminal, the second TVS terminal for connection toa second external voltage line, wherein the crowbar device and the TVSdevice are arranged in electrical series between the first crowbarterminal and the second TVS terminal; wherein the TVS device and thecrowbar device are disposed within a common semiconductor substrate, thecommon semiconductor substrate comprising: a first surface, the firstsurface forming a first portion of the first crowbar terminal; and asecond surface, opposite the first surface, the second surface forming asecond portion of the second TVS terminal.
 2. The overvoltage protectiondevice of claim 1, wherein the TVS device comprises a Zener diode, anavalanche diode, or TVS diode.
 3. The overvoltage protection device ofclaim 1, wherein the TVS device comprises a pair of TVS diodes having acathode-to-cathode configuration.
 4. The overvoltage protection deviceof claim 1, the common semiconductor substrate comprising: a firstN-doped region, the first N-doped region being disposed adjacent to thefirst surface; a first P-doped region, the first P-doped region beingdisposed adjacent the first N-doped region and surrounding the first Ndoped region within the common semiconductor substrate; a second N-dopedregion, the second N-doped region being disposed adjacent the firstP-doped region, wherein the second N-doped region and first N-dopedregion do not share a common interface; a third N-doped region, thethird N-doped region being disposed adjacent the second surface; and asecond P-doped region, the second P-doped region being disposed betweenthe second N-doped region and the third N-doped region, and surroundingthe third N-doped region within the common semiconductor substrate. 5.The overvoltage protection device of claim 4, further comprising: anN+doped surface region disposed adjacent the first surface andoverlapping the second N-doped region and first P-doped region, theN+doped surface region being disposed outside of the first N-dopedregion.
 6. The overvoltage protection device of claim 4, furthercomprising: at least one N+doped buried region, the at least one N+dopedburied region being disposed between the first P-doped region and thesecond N-doped region, and under the first N-doped region.
 7. Anovervoltage protection assembly, comprising: a first semiconductor chip,the first semiconductor chip comprising a crowbar device; and a secondsemiconductor chip, the second semiconductor chip comprising a TVSdevice and being electrically connected to the first semiconductor chip;wherein the overvoltage protection assembly comprises a first externalterminal forming contact with the crowbar device, the first externalterminal for connection to a first external voltage line, and whereinthe overvoltage protection assembly comprises a second external terminalforming contact with the TVS device, the second external terminal forconnection to a second external voltage line, wherein the crowbar deviceand the TVS device are arranged in electrical series between the firstexternal terminal and the second external terminal; wherein the TVSdevice and the crowbar device are disposed within a common semiconductorsubstrate, the common semiconductor substrate comprising: a firstsurface, the first surface forming a first portion of the first crowbarterminal; and a second surface, opposite the first surface, the secondsurface forming a second portion of the second TVS terminal.
 8. Theovervoltage protection assembly of claim 7, wherein the TVS devicecomprises a Zener diode, an avalanche diode, or TVS diode.